As we move from a land of plenty to a land of uncertainty, what can be done to combat the food crisis?

Mexican tortilla chip riots, empty shelves in Venezuela, beef export bans in Argentina, export taxes on Russian wheat and pasta protests in Italy.

Changes in supply and demand are impacting on agricultural production and food commodity prices. With raw material prices rising, consumer price hikes are inevitable. Current food inflation is well above general inflation, reversing the trend of the past 20 years. The era of cheap food is over.

Much has been written about the unprecedented change that society faces today, but few appreciate the full extent or nature of the changes that are taking place. This will be the tipping year. For the first time, more people will live in cities than in rural areas. The balance between people who need to buy food and those who subsist on the land has shifted forever.

It is predicted that by 2015, 66 million more people will live in mega-cities of 10 million-plus inhabitants. While China's population is relatively stable, this is not so in India. One in every six of the world's population will live in India by 2020. By 2050, only 7% of the world's population will be located in Europe.

The effect of urban migration on food demand is pronounced. As wealth increases, people's eating habits change as they can afford to eat more meat, dairy, fruits, vegetables and oils. But meat production requires substantially more land than crops to produce the same calorific intake.

Add together the increases in population and wealth, and current projections are that world food consumption will double by 2050. Biofuel production could equal this increase in demand. Potentially we need to triple the total amount of crop production in the next 40 years from a reduced land area.

Climate change is compromising the availability of land for agriculture. Australia has gone through two bad years with drought, severe reductions in the cereal harvest and substantial devastation to pasture land. The Iberian peninsula is currently in a critical state with seriously low water reserves. And in the UK, last summer's floods severely compromised large areas of vegetable production and reduced the country's wheat yield.

We have taken for granted safe, cheap, consistent-quality food produced in an environmentally sensitive way, but this is no longer a given.

Inertia in government is one of the threats to the UK's socio-economic and environmental wellbeing. These global changes in societal needs require radical changes in strategic thinking. Hearteningly, his week's conference 'From a Land of Plenty to a Land of Uncertainty' brought together leading thinkers, opinion formers and industry to debate solutions.

If we act now we can step back from the brink of these projections and moderate these unsustainable demands on our planet. If we do not, then politicians, food companies and consumers will have some stark, unpalatable choices to make.

This is perhaps the greatest challenge of our time - how to grow more consistent, affordable food, whilst safeguarding the environment, welfare and safety to feed not just ourselves, but the world's ever-growing and wealthy population.

The alternative is grim: either we have to give up some of our standard of living or the developing world cannot improve theirs. And with economic power shifting from West to East, that point has already passed. n

Sir Ben Gill CBE MA (Cantab) is executive director of

Hawkhills Consultancy Ltd.